Belt-tensioning device



Dec.- 13, 1927. Y

E. ROBERTS BELT TENSIONING DEVICE 3 Sheets-Sheet 1 Filed July 28. 1924 Eliri.

, JZiUka Dec. 13, 1927. 1,652,799

E. ROBERTS BELT TENSIONING DEVI CE Filed July 28, 1924 s Sheets-Sheet 2 Dec. 13, 1927.

E. ROBERTS BELTYTENSIONING DEVICE Filed July 28. 1924 S SheetsSheet {5 Patented Doe.

UNITED STAT-Es j PATEnr orr clz.

flammnonnn'rs, or LAKE an mun, ass'renon mo "rm: 's'rarns nenmn COMPANY, or-san'r LAKE man, a conrom'non or man.

BELT-"mansions nnv rcn Application fled m 2a, 1624. Serial at. "72am.

Tihis invention relates to belt tensioning devices, and is particularly'intendedtodpror1v- -vide a device of this class suitable'fhr ing a battery of centrifugal machines from: Q a horizontal line shaft by means of quarter- I turn belts running from individual drivin pulleys on the line shaft to. the centrifuga pulleys secured to the vertical basket shafts in order to rotate the separate centrifugals at the Genera y s eaking, the invention comprises the com ination of a.fixed base member carrying a slidin carriage on which is Ymounte an idler pu ey'hanger'by means of a connection permitting angular ad'ustment of the pulley and hanger to adapt-1t to the position of the quarter-turn belt, and a weight-actuated lever having suitable con-. nection with the hanger-supportin carria e '20 to maintain the idler pulley presse strong y against the transmission belt. through the" 'weight-induced movement of the sliding'carriage. The invention also resides in certainv features of construction which ermits the reversing of the pulley, that is, its arrangement eitherabove or below its supporting base-{according to the relative vertlcal location of the belt-driving pulley.

. These and other features of the invention' will be pointed out in the followingspecification and will be defined in the claims "hereto annexed. i r Inthe accompanying drawings I have shown a simple and convenient construction 5' and arrangement embodying the features of this invention, in which:

{0 porting base.

I Y tor-turn v transmission ing oxes broken awa Figurel is a side elevation, part1 in central section, showing the idler pu eyflsupported on its carriage above the fixed sup- Fi re 2 is an end elevation with the bearthrust-supporting radia bearings.

Figure 3 is-a detail view in central cross .45 section of the supporting base and the lower part of the hanger and carriage.-

I Figure 4 is a side elevation showingan assembled view of the tensionin device in relation to the drivingxpulley an the quart. v

Figure 5 is a plan view of that portion of the carria e forminguthe support for the aner hanger.

bolted firmly to the corresponding .of the carriage 4,- by means of vertical bolts to show the end' ter-turn belt. j In order to keep the fidlerpulley' ressed.

In this case, on the channel beam 1, is bolted a fixed base member 2, which is protensioning device issecured, as indicated in r Figures ,1, 2 and 4 especially.

sided with parallel up-turned and inwardly projecting ribs or track members 3 forming longitudinal 'ways for the reception and slidable sup ort of a carriage 4 which has parallel slide portions 4f, machined to fit inside of the guide ribs 3, so as t'o'have' slidable connection therewith.

The flat top of said carriage 4 is adapted to receive a corresponding head 5 of an idler pulley hanger which is provided with parallel upstanding arms 5 carrying, at their ends, bearing boxes 5", for the reception of the journals of the idlerpulley. To avoid lossv of power and also to-pro erly sustain any side stresses due to the unba anced strain of the quarter-turnbelt which passes over the idler pulley boxes 5 with radial ball-bearing elements '25, com rising outer andinner annular races interior grooved to a sufficient depth to adequate y sustain side thrust or axial 6, l'providethe bearingthrust of the idler pulley journals. Exterior caps 25 close the outer ends of the journal boxes. p

Thehead 5 of the idler pulley hanger is portion 4, v pas'sin through appropriate holes formed in t e head 5 to register with curved ,slot's 4 ,formed in the supporting carriage, in order that the hanger may be adjusted and secured in the roper angular relationship, to best meet e .stresses of the quarsnugly against the belt to maintain t e belt 'in taut condition, I provide a we1ght-actu ated lever 9 to whose free end is pivotally connected a yoke or strap 10, which receives roe a draft-rod 8 which is screw-threaded and no no has loose engagement with the cross memberof a yoke 10 through whichit passes, and by its threaded engagement with the swivel block 7, which, is pivotally secured to the carriage, it has an adjustable draft connection with the carriage. The weight-actuated lever 9 is pivotally supported at one end of the device by means of a projecting detachable forked bracket 12, which carries a'fulcral pin 12*, upon which. the lever is pivoted. Y

Then the pulley is mounted above the belt, as in Figure 1, in order to avoid extending the weight-carrying arm still farther out be yond the tensioning device, the lever 9 is provided with a short arm in the form of a sector gear 9 and interineshes with a similar sector arm 11 of a lever 11, fulcrumed at 11 in the bracket, and a weight-rod 13 is secured -to the lever 11 with an adjustable weight 14 slidably' mounted thereon and secured in proper position of adjustment by said screw 145% A protective strap or loop 15 extends downward around the weight so as to hold it againstdropping too far in case the belt lacing should break.

The pivotal connection between'the draft rod 8 and the weight-actuated arm 9 at one end, and-the carriage at the other end allows full freedom of movement to the carriage without binding of parts, and permits a very easy and convenient adjustment between the weight-actuated 'lever and the idler pulley carriage when the belt becomes stretched since, in order to accommodate such.condition it is merely necessary to rotate the draft rod 8 until the weight arm 13 extends approximately at a horizontal positionwhen the idler pulley has exerted its normal tension against the belt to press the belt toward its driving pulley. The driving pulley itself,

by reason of its angular adjustment in rela-' tion to its supporting carriage, as well as by reason of its anti-friction radial bearings arranged to resist the axial thrust of the pul ,ley, functions with the least possible'loss of power and also is completely responsivegto its duty oflkeeping the belt under a constant or uniform tension.

What I claim is; 1. Ina belt tensioning, device, the combination with a fixed base, a carriage slidably mounted thereon by connections permitting the base and the carriage to operate when arranged in inverted position, a weight-actutated lever having'reversible connection with 7 said carriage, an idler-pulley mounted on said carriage and normally pressed against the belt by the action of the weight-actuated lever on the carriage, substantially as described.

.2. In a belt tensioning device, the combination of a base, a slidable carriage supported thereby, a pulley-supporting hanger secured to said carriage to permit angular ad' justment of the pulley in relation to a quartor-turn belt, said hanging being provided with radial ball bearings arranged to sustain axial stress of the pulley, and an actuating lever interconnected with said carriage to maintain the pulley in tensioning contact with the belt, substantially as described.

3. In a belt-tensioning device, the combinationwith a fixed base, of a slidable carriage, a belt pulley hanger secured to said carriage, a draft-rod 'pivotally connected with the carriage, a tensioning weight arm interconnected to the draft-rod by a combined pivotal and swivel connection to permit the draft rod to be rotated for longitudinal adjustment in order to bring the'weightarm into proper operative position for effectively tensioning the belt.. I

4. In a belt-tensioning device, the combination with a fixed base, a carriage slidably connected therewith, a belt-pulley hanger, means for securing said hanger to the carriage in different angular relations, a rotatively adjustable draftrod having pivotal connection with said carriage, a weight-actuated arm having its pivotal connection with said draft-rod to'allow the rotation of said draft-rod for adjustment, substantially as described.

5. In a belt-tensioning device, the combination with abase member adapted to be secured either above or below a supporting member to permit its adjustment in reverse positions, a slidablecarriage slidably mounted in said base, a belt-pulley hanger rigidly secured thereto by connections permitting angular adjustment, a longitudinallyadj'ustable draft-rod connected with said carriage,

a reversible weight arm and lever connected 1 with said draft-rod so as to produce tension of'the pulley against the belt when the base is reversed to bring the pulley underneath.

, 6. In a belt-tensioning device, the combination with a fixed base, of a slidable carriage mounted to slide therein, .a weight-actuated arm, a link pivotally connected with said weight-actuated arm, a draft-rod having rotative connectionwith said link and having also rotative: and adjustable connectionlwith said carriagewhereby, upon rotation with the draft-rod, the carriage may be positioned to belt-tensioning position with the weight arm in proper position to exert a 

